Aircraft flight indicator



DGC. 5, 1944. J. w S E JR 2,364,102

AIRCRAFT FLIGHT INDICATOR Filed NOV. 16, 1943 INVENTOR c/orwv 14/ 658544 45 BY r.

Patented Dec. 5, 1944 AIRCRAFT menminicnoa John W; Sessums, Jr., Washington, Ii-G. e H Application November is, 1943-, Serial No. 10,,52 5 I I 2 Claims. (01. "73 -178) 1 l (Granted underthe act 01' March a, 1883, as amended April so, 1928;, 3709. 6. 757

The invention described herein maybe manufactored and used by -or for the Government for governmental purposes, without the to me of any royalty thereon.

This invention relates to flight indicators for payment aircraft and more particularly to a novel type of indicator for signifyingto the pilot of the craft whether ornot his craft is flying-along landing approach into an airport,

In several of the presently known types of blind landing systems the pilot brings the aircraft into the airport by flyingat a predetermined attitude until amark-er beacon is reached after which the engine is 'throttled down and the the particular glidepath prescribed for a blind l airplane caused to follow a prescribed glide path until the wheels touch the runway, the motor then being cut oif and the-airplane brought to a,

step. In making this type of approach it is very difiicult for the pilot to holdthe-aircraft on the prescribed glide path inasmuch as the indications of two "separate instruments must be continually observed in order tokeep thea'irplane on course. Ihese two instruments are the airspeed indicator and the rate of-climb indicator, it being necessary that both the air speed of the craft and the rate of descent thereof be maintained at predetermined values in order to stay I on the prescribed glide path. I

"The principal object of the present invention is to combine an air-speed indicator and arateof-climb indicator into a single instrument which will quickly indicate to thepilot whethero-r not his aircraft is following the proper glide path, and; if not, what steps'shouldbe taken to bring the craft back on course."

Amore particular object of this invention is to so arrange the indicatingelements of the composite instrument that the pilot can seeat a glance whether or not'his approach is being made correctly. In order to accomplish this, the elements are so arranged as to indicate; in a natural and logical fashion whether or not the air speed and rate of descent are correct, or whether the air speed is too slow or too fast or the rate of descent too steep or too flat.

It is recognized that air-speed and rate-ofclimb indicators have previously been combined into a single "instrument, such instrument being the one shown in U. S. Patent No. 2,152,635 of Carl J. Crane, et al., issued April l, 1939. In this device, however, the two indicators were combined for the purpose of indicating whether or not the aircraft was following a normal cruising course rather than whether or notit was following aprescribed glide" course. In the present invention, a conventional air-speed indicator and a conventional *rate-of-climb "indicator cooperate in a novel manner to produce a visual representationofthe position of the aircraft with respect to the prescribed glide path. I

a In the particular embodiment of the inventio herein shown and described, I have disclosed a preferred form of apparatus for carrying out my inven'tion,--but'it is to be understood thatthe invention is not necessarily limited to the specific type of construction herein disclosed, but

instead includes all structures which come within the scope of the claims appended heretofl ln the drawingz Figure 1 is a perspective View apparatus which may be used infcarrying out my invention. The-parts are shown in the positions which-they occupy 'when the aircraft is approaching the airport at the proper speed and l at the proper rate of descent;

Figure "2 shows the position which the pointers assume when the aircraftis flying at too high speed, and at ,an insufiicient rate of descent;

*Figure 3 shows the pointers in the position which they assumewhen 'the aircraft is flying a-t'too'low a rate of speed-and attoo great a'rate of descentl o l Asshown inFigure having the customary handstafi ll. Suitable provision should be made for reversing the direction of movemen't of -the handstafi so that it I will-move in a counterclockwise direction with an increase in-air speed rather than in a clockwise direction asis customary in conventional air speed indicators. This maybe accomplished either-by means ofsuitable gearing within the instrument or by reversing one of the lever arms therein so as to reverse-the movement of the handstaff. A conventional rate-of-climb indicator I2, having the usual handstaff I3, is located below and toone side of the air-speed indicator. The two indicators l0 and I2 may be maintained in the positions which they occupy in Figure 1 by means of a suitable supporting frame or plate (not shown) to which they maybe rigidly attached. The conventional hands usually provided onthe instruments l0 and I2 are removed and replaced with elements which are more suitable for the purpose of carrying out my invention. For example, to the handstafi I I of the air-speed indicator is attached a hand I4 which carries at its outer end a light loop or ring l5, while to a handstaif l3 of the rate-of-climb indicatoris atof oneform of 1, reference numeral l fl 3 designates a conventional air-speed indicator tached a hand I6 which is provided at its outer end with a small facsimile of an aircraft H. A

dial I8 having suitable indicia I9 inscribed thereto the path of movement of the airplane H. j

across the dial. Furthermore, the instrument I2 is so positioned that the axis of the handstaff I3 will lie on the glide path I9 extended. As hereinbefore stated, the ring I5 and the airplane II are shown in Figure 1 in the positions which they occupy when the air speed and rate of descent of the aircraft are correct for the particular glide path chosen. The handsIlI and I6 may be made to assume these positions for a given air speed and rate of descent by locating the hands on the handstaffs II and I3 in approximately the correct positions to indicate this condition, Minor adjustments in these positions may then be made by means of the usual zero-adjust mechanisms incorporated in the instruments. If the air speed of the aircraft is greater than that selected for the approachinto the airport, the ring I5 will move to the right, as shown in Figure 2, so as to indicate that the airplane is traveling too fast. If the airplane is moving at a slower speed than that chosen for the approach, the ring I5 will move to the left as shown in Figure 3 so as to show that the airplane is lagging behind or moving too slow. Similarly, when the aircraft is not descending fast enough to stay on the properglide path, the

airplane I! will move upwardly as shown in Figpresent purpose, it will be necessary to adjust the conventional diaphragm limit stops on the instruments so as to prevent thering I5 and the airplane I! from moving off the dial I8 when the aircraft is at rest, flying at high speed, performing acrobatic maneuvers, etc.

It will thus be seen that I have combined an air-speed indicator and a rate-of-climb indi-- cator in such a manner as to show at a glance the position which the aircraft'bears with respect to a prescribed glide path. The indication given by the improved instrumentis such as to quickly show whether or'not the aircraft is on course and, if not, in what manner the air speed or rate of descent should be corrected to place the aircraft in the proper attitude for a perfect approach. It is to be realized, of course, that the construction herein shown is not the only one possible in. carrying out my invention and that variations may be made in the general scheme of the apparatus without departing from the real invention therein,

I claim:

1. An aircraft flight indicator comprising an indicator dial, indicia on said dial representing a prescribed glide path for the aircraft, a sub stantially circular indicating element adapted for movement along said indicia in accordance with the air speed of the aircraft, said element being arranged to occupy a position midway along said indicia when the aircraft is traveling at a certain desired air speed, and an element'in "the form of a miniature aircraft adapted for movement in accordance with the rate of descent of the aircraft along a path lying substantially at right angles-to said indicia and intersecting the latter at its midpoint, said last-named element being smaller in size. than said circular indicating element and arranged to lie directly over said indicia when the rate of descent corresponds to a certain desired value, whereby the miniature aircraft elementwill lie on the indicia representing the prescribed glide path and in the center of the circular indicating element when the aircraft is traveling along the prescribed glide path at the proper speed. l

2. An aircraft glide path indicator comprising a frame, an air-speed indicator secured to said frame, said air-speed indicator having an airspeed pointer, .a rate-of-climb indicator secured to said frame, said rate-of-climb indicator having a rate-of-climb pointer, an indicator dial secured to said frame, indicia on said dial representing a prescribed glide path for an aircraft, a substantially circular ring secured to the end of said air-speed pointer andadapted to move along said indicia, said ring beingadapted to occupy the position midway along said indicia when the aircraft is traveling at a certain desired air speed, and an element in the form of a miniature aircraft secured to the end of said rate-of-climb pointer, said element being smaller in size than said ring and adapted to move along a path lying substantially at right angles to said indicia and intersecting the latter at its midpoint, said element also being adapted to lie directly over said indicia when the rate of descent of the aircraft corresponds to a certain desired value, whereby theminiature. aircraft device will lie on theindicia representing the prescribed glide path and in the center ofv the ring when the aircraft is gliding at the proper angle and .speed.

- V JOHN W. SESS-UMS, JR. 

